Matter and Measurement Flashcards
is the field of study concerned with the characteristics, composition, and transformations of matter
Chemistry
includes all things, both living and non-living.
Matter
Physical state
Solid
Liquid
Gas
characterized by a definite shape and a definite volume
Solid
characterized by an indefinite shape and a define volume
Liquid
characterized by an indefinite shape and an indefinite volume
Gas
distinguishing characteristic of a substance that is used in its identification and description
Property
characteristics that can be observed without changing the basic identity of the substance (ex. Color, odor, physical state, melting/boiling point, hardness)
Physical property
describes the way the substance undergoes or resists change to form a new substance
Chemical property
a substance changes its physical appearance but not is chemical composition (ex. Changes in physical state)
Physical change
a substance undergoes a change in chemical composition. It always involve conversion of the material under consideration into one or more new substances
Chemical change
a single kind of matter that cannot be separated into other kinds of matter by any physical means
Pure substance
-physical combination of two or more pure substances in which each substance retains its own chemical identity
-One characteristic of any mixture is that its components can be separated using physical means
Mixture
a mixture that contains visible different phases (parts), each of which has different property
Heterogenous mixture
contains only one visibly distinct phase (part), which has a uniform properties throughout (ex. Sugar-water mixture)
Homogenous mixture
pure substance that cannot be broken down into simpler pure substances by chemical means
Element
pure substance that can broken down into two or more simpler pure substances by chemical means (ex. Water [H2O] can be broken down into the elements hydrogen and oxygen)
Compound
Notes: Compounds vs Mixtures
-Remember, substances can be combined either physically or chemically
-No such binding occurs during physical combination
Notes:
-Physical combination of substances produces a mixture
-Chemical combination of substances produces a compound, a substance in which combining entities are bound together
The discovery and isolation of the 117 known elements, the building blocks for all matter, have taken place over a period of several centuries. Most of the discoveries have occurred since
1700, the 1800s being the most active period
Note: Elements
Each element has a unique name; some bear geographical names (germanium, francium and polonium), some are named for the planets (mercury, uranium, neptunium), some reflect specific properties of the element or of the compounds containing it
one- or two-letter designation for an element derived from the elementβs name
Chemical symbol
is the smallest particle of an element that can exist and still have the properties of the element
Atom
Note:
-A sample of any element is composed of atoms of a single type, those of that element. In contrast, a compound must have two or more types of atoms present, because by definition at least two elements must be present
-Free atoms are rarely encountered in nature
-Atoms are almost always found together in aggregates or clusters
is a group of two or more atoms that functions a unit because the atoms are tightly bound together
Molecules
is a molecule that contains two atoms, a triatomic molecule contains three, and so on.
diatomic molecule
is a molecule in which all atoms present are of the same kind. Substances containing (ex. Hydrogen [H2], oxygen [O2], nitrogen [N2], and chlorine [Cl2])
homoatomic molecule
is a molecule in which two or more kinds of atoms are present.
heteroatomic molecule
Note:
-The atoms present may all be of the same kind, or two or more kinds may be present
-Substances containing heteroatomic molecules are compounds (ex. Water [H2O]
molecules made of atoms from different elements
Compounds
atoms connected by chemical bond
Molecules
Note:
ALL COMPOUNDS ARE MOLECULES, BUT NOT ALL MOLECULES ARE COMPOUNDS
H2 is a molecule, but not a compound (only H is present)
H2O is both a molecule and a compound (H and O are present)
is a notation made up of the chemical symbols of the elements present in a compound and numerical subscripts (located to the right of each chemical symbol) that indicate the number of atoms of each element present in a molecule of the compound.
chemical formula
determination of the dimensions, capacity, quantity, or extent of something
Measurement
Note:
There are two systems of measurement that is used commonly: The English system of units and the metric system of units
Examples of units in the English system are
inch, foot, pound, quart, and gallon
Examples of units in the metric system are
gram, meter, and liter
Examples of units in the metric system are
gram, meter, and liter
Note: Metric System Units
-In the metric system, there is one base unit for each type of measurement
-Prefixes are then added to the base unit
-The meter (m) is the base unit of length in the metric system (1 m is equivalent to 1.09 yards)
-The gram (g) is the base unit of mass in the metric system (28 g = 1 ounce, 454 g = 1 pound)
-The liter (L) is the base unit of volume in the metric system (1 L is equivalent to 1.06 quarts)
Measurements will always have a degree of uncertainty or error
Uncertainty in Measurements
are digits in a measurement that are known with certainty plus one digit that is estimated
Significant figures
are digits in a measurement that are known with certainty plus one digit that is estimated
Significant figures
note:
-Uncertainty is indicated by the number of significant figures recorded
-Number of significant figures = all certain digits + one estimated digit
. In multiplication and division, the number of significant figures
that contains the fewest significant figures
In addition and subtraction, the answer is given with as many significant figures as the measurement with the
least number of decimal places
is a numerical system in which numbers are expressed in the form A X 10n, where A is a number with a single nonzero digit to the left of the decimal place and n is a whole number
Scientific notation
Note:
-The coefficients are combined in the usual way (multiplied or divided)
-The rules for exponential terms are:
1. To multiply exponential terms, add the exponents
2. To divide the exponential terms, subtract the exponents
Ex. (2.33 x 103) x (1.55 x 104)
2.33 x 1.55 = 3.61
103 x 104 = 103+4 = 107
Final answer is 3.61 x 107
is a ratio that specifies how one unit of measurement is related to another unit of measurement
It is derived from equalities that relate units
Ex. 1 minute = 60 seconds
A pair of conversion factor can be derived from this equality
(1 ππππ’π‘π)/(60 π ππππππ ) and (60 π ππππππ )/(1 ππππ’π‘π)
Conversion Factors
is a general problem-solving method in which the units associated with numbers are used as a guide in setting up calculations
Dimensional Analysis
-is the ratio of the mass of an object to the volume occupied by that object
-Generally expressed in grams per cubic centimeter (g/cm3) for solids, grams per milliliters (g/mL) for liquids
π«ππππππ
π«ππππππ formula
π«ππππππ= ππππ/ππππππ
is a form of energy. Temperature is an indicator of the tendency of heat energy to be transferred
Heat
Note:
-Heat energy flows from objects of higher temperature to objects of lower temperature.
-Both the Celsius and the Kelvin are part of the metric system; Fahrenheit scale belongs to the English system
-The Celsius scale is the most commonly used in scientific work
